Effect of aqueous extract of Iranian Sumac (Rhus criaria L.) on the shelf life of Hypophthalmichthys molitrix fillet during storage at 4◦C

Sumac (Rhus coriaria L.), belonging to the Anacardiaceae family, grows in Mediterranean countries, North Africa, South Europe, Afghanistan and Iran. The sumac berries contain biological activities such as antioxidant, antimicrobial, hypoglycemic and antidiabetic. The present study examined the effects of water extract of sumac on the chemical, microbiological and sensory quality on silver carp (Hypophthalmichthys molitrix) fillets during storage at 4๐C. Treatments in the present study included the following: Control without extract of sumac, 1, 2.5 and 5 % (w/v) the water extract of sumac. After 18 days of storage, the results showed that the lowest total viable count (TVC) (7.34 log 10 cfu g-1), psychrophilic total counts (PTC) (7.21 log 10 cfu g-1), pH (6.43), total volatile basic nitrogen (TVB-N) (23.38 mg N 100g-1), Thiobarbituric acid (TBA) (1.66 mg MDA kg-1) and peroxide value (PV) (5.28 meq kg-1) were recorded in 5% sumac water extract treated samples, while the highest TVC (9.01 log 10 cfu g-1), PTC (8.97 log 10 cfu g-1), pH (7.15), TVB-N (38.71 mg N 100g-1), TBA (2.82 mg MDA kg-1) and PV (9.41 mEq kg-1) occurred in the control group. The best outcome of sensory evaluation was acquired in samples that treated with 5% sumac water extract and was significantly different (p≤0/05), when compared to the control group after 18 days of storage. Natural preservatives such as sumac extract can be used as a safe method for storage of silver carp fillets, which is quite promising for food industry.